Rexroth IndraDrive
9
Control Mains Contactor
9.1
Control Possibilities
Shutdowns with Faulty Drive Electronics
Braking with Emergency Stop or Power Failure
9.2
Controlling the Supply Unit with Emergency Stop Relays
With DC Bus Dynamic Brake
DOK-INDRV*-HMV-*******-PR01-EN-P
The controls of the mains contactor and of the DC bus dynamic brake in
the supply unit, that are suggested in this documentation, explain the
function principles. In this chapter, several control options are discussed
and explained.
Note:
Which control and functions are selected ultimately depend on
the extent of functions required and the range of actions of the
entire installation and is primarily the responsibility of the
manufacturer.
An additional safety for braked shutdowns of the drives in case of faulty
drive electronics is to short-circuit the DC bus voltage.
If the DC bus voltage is short-circuited, the motors with permanent
energized magnet will always be shut down to a braked condition. This is
the case whether the drive electronics is operative or not.
Note:
Asynchronous drives do not brake when DC bus voltage is
short circuited!
If the drive electronics is interfered and the DC bus voltage is not short-
circuited, then the motors with energized permanent magnet will slow
down uncontrolled.
In an emergency stop or power failure situation, drives are generally
shutdown by the drive control.
Given an emergency stop or with actuation of the drive-internal monitor,
the drive control command value is set to go to zero and the drives brake
controlled at maximum torque.
In some applications, however, e.g., electronically-coupled gear cutting
machines, it is necessary to bring the drives, given an emergency stop or
power failure, to a standstill controlled by the CNC. In an emergency stop
situation or given the actuation of the drive-internal monitor, the drives are
shutdown position-controlled by the NC control.
If the mains contactor in the supply unit is controlled via the emergency
stop relay and the DC bus is short-circuited, you will reach maximum
safety possible thus with very little expenditure. The drive system
monitors are most effectively used.
Control Mains Contactor
9-1